Which process uses chemical energy to power all of a tree's biological functions?

• A. Respiration
• B. Photosynthesis
• C. Transpiration
• D. Germination

Answer: (A)

Cellular respiration uses chemical energy to power all of a tree’s biological functions. In respiration, cells break down sugars to release energy and generate ATP, the energy currency that drives every active process—from growth and repair to nutrient transport and metabolism. This energy comes from sugars produced by photosynthesis, but respiration is the process that converts that chemical energy into usable ATP to run the tree’s cells. Photosynthesis captures light energy to build sugars; transpiration moves water and nutrients, and germination is the initial growth phase from a seed—none of these directly provide the ongoing cellular energy that respiration supplies.